Ontario Construction News staff writer
As Strabag crews continue to prepare the entry point for tunnelling of the Scarborough Subway Extension, workers halfway around the world are building the project’s tunnel boring machine that will travel across the Atlantic Ocean.
In Schwanau, Germany, a small town on the border with France, workers are manufacturing the machine itself, commonly referred to as a TBM.
A big, single tunnel needs a big tunnel boring machine, says Joshua Patel, senior advisor, subway program at Metrolinx. The machine will build a tunnel with a 10.7 metre diameter, soon to be the largest subway tunnel in Toronto. The 7.8-kilometre Scarborough Subway Extension will be the first subway project in Toronto to operate in both directions within a single tunnel, requiring only a single boring machine to create all the necessary space.
The TBM for the Scarborough Subway Extension is being manufactured by Herrenknecht, the company that has supplied tunnelling technology for underground infrastructure around the world, including major subway projects in the UK and around Europe.
After quality control and testing at the Herrenknecht facility, at the end of September, the massive machine will be dismantled and will travel in multiple shipments to Canada by boat.
The TBM shipments are expected to arrive in early 2022 and then travel by truck to the launch shaft site at McCowan Road and Sheppard Avenue, where crews will re-assemble the machine.
Later in the spring, crews will lower the assembled machine into the ground so it can begin tunnelling its way south under McCowan Road, digging about 10 metres each day.
